Quiet moment not at home (4)
I believe the answer is:
mute
'quiet' is the definition.
(I've seen this in other clues)
'moment not at home' is the wordplay.
'moment' becomes 'minute' (both can mean a short amount of time).
'not' is a deletion indicator.
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'minute' with 'in' taken away is 'MUTE'.
(Other definitions for mute that I've seen before include "Unspeaking" , "Soften the sound" , "Unable to speak" , "Deaden sound of" , "Speechless, soundless" .)